Albert Einstein presents the field equations of general relativity to the Prussian Academy of Sciences, describing gravity as the curvature of spacetime.
Archduke Franz Ferdinand of Austria-Hungary and his wife are shot dead by Gavrilo Princip in Sarajevo, triggering the crisis that leads to the First World War.
Austria-Hungary declares war on Serbia, drawing Europe's powers into a global war that lasts until the armistice of 11 November 1918.
Irish republicans rise in Dublin and proclaim an Irish Republic; the rebellion is put down by British forces after six days.
Britain and France secretly agree to divide the Ottoman Empire's Arab lands into post-war spheres of influence.
Igor Stravinsky's ballet The Rite of Spring premieres in Paris amid uproar in the audience, becoming a landmark of modernist music.
The Bolshevik Red Army fights the White movement and other forces after the October Revolution; the Bolsheviks emerge victorious.